The 19-year-old singer and his friends are suspected of using the substance as they made their way to the airport, TMZ.com reported.
The pilot, who was enlisted to fly the plane, claimed that he was astounded by the strong smell of weed when the ‘Baby’ hitmaker’s car opened.
The pilot said that he almost had to put on an oxygen mask. However, Bieber is said to have behaved well and refrained from smoking, unlike his posse who lit up a smoke in the flight.
The pilot also claimed that the popstar wasn’t totally aware of what he was doing and got confused when he was signing a credit card bill.